The stability and modulation of if-then rules versus prospective planning in movement selection under dual-tasking conditions.

Two approaches to movement selection, if-then rules versus prospective planning, were investigated. Studies have shown that the rule-based approach leads to more efficient movement selection than the plan-based approach, though the resulting movements are the same. This dual-tasking study investigates two hypotheses explaining this discrepancy: The efficiency hypothesis states that the rule-based approach to movement selection is more efficient, and its advantage over the plan-based approach increases under any kind of enhanced task demands.